Mars Once Had Large Oceans

The once-flat shorelines were disfigured by a massive toppling over of the planet, scientists announced today. The warping of the Martian rock has hidden clear evidence of the oceans, which in any case have been gone for at least 2 billion years.

Somewhere along the way to toppling over 50 degrees to the north, Mars probably lost some of its water, leaving the Deuteronilus Ocean's shoreline exposed. "The volume of water was too large to simply evaporate into space, so we think there is still some subterranean reservoirs on Mars," Perron said.

The remaining sea would have been located in the same lowland plain as the Arabia Ocean, but almost 40 degrees to the north.

Near the equator, the surface of a planet stays in a relatively flattened bulge under the pressure of centripetal forces. But outside of the equator, the rock behaves elastically and often bunches up, like the surface of a deflating balloon. Perron and his team reasoned that the oceanic shorelines were once near the equator, but warped into hilly up-and-down elevations of rock as they move towards the north with the tilting planet.